Cancer genetics involves the detailed study of mutations at the molecular level. Cancer is simply due to the mutations at the genetic level, commonly known as genetic disorder. In this condition the cells suffer from a uncontrolled growth of cell division. These mutation cans be acquired or may occur in somatic cells. Somatic cell mutations cannot be inherited while germ line mutations are inherited. The mutations are prone to occur in proto-oncogene and tumour suppressor gene which in wild state helps in preventing the occurence of cancer.